1. Field of the Invention
The present invention relates to a vapor-compression refrigerant cycle in which high-pressure refrigerant discharged from a compressor is radiated and a low-pressure refrigerant after being decompressed is evaporated. More particularly, the present invention relates to an ejector cycle having an ejector in which a mixture refrigerant is used.
2. Description of Related Art
In an ejector cycle described in U.S. Pat. No. 6,438,993 (corresponding to JP 2002-323264), high-pressure refrigerant is decompressed and expanded in a nozzle of an ejector in iso-entropy, and the liquid-phase refrigerant separated in a gas-liquid separator is supplied to an evaporator by the pumping function of the ejector. Further, in the ejector cycle, a pressure of refrigerant to be sucked into a compressor is increased by converting an expansion energy to a pressure energy, so that consumption power of the compressor is reduced.
In this ejector cycle, as expansion energy recovered in the ejector, that is, an adiabatic heat drop in the decompression and expansion becomes larger, the consumption power of the compressor can be made larger. Further, as a converting efficiency becomes higher while the speed energy is converted to the pressure energy in the ejector, a suction pressure of the compressor is increased, and the consumption power of the compressor can be effectively reduced.
Further, a cooling capacity (heat absorbing capacity) can be increased in the evaporator by using a mixture refrigerant in a vapor-compression refrigerant cycle. However, it is difficult to improve coefficient of performance in an ejector cycle by reducing consumption power of the compressor, when the mixture refrigerant is simply used as the refrigerant.